Question

A new cola company is testing to see what proportion of their cans contain at least 12 oz. If they want to be within 3% of the actual percentage, how many cans should they measure to be 90% confident

Answer 1

Answer: 752

Explanation:

Given that,

Margin of error = 3% = 0.03

confidence level = 90% = 0.90

therefore from the z-table

z = 1.645

Now since no prior estimate of p is given, so we say p = 0.5

Sample size required will be

n = 1.645² × 0.5 ×(1-0.5) / 0.03² = 751.67

n = 751.67 ≈ 752